/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.transaction;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Exception thrown when a general transaction system error is encountered,
 * like on commit or rollback.
 *
 * @author Juergen Hoeller
 * @since 24.03.2003
 */
@SuppressWarnings("serial")
public class TransactionSystemException extends TransactionException {

    @Nullable
    private Throwable applicationException;


    /**
     * Constructor for TransactionSystemException.
     *
     * @param msg the detail message
     */
    public TransactionSystemException(String msg) {
        super(msg);
    }

    /**
     * Constructor for TransactionSystemException.
     *
     * @param msg   the detail message
     * @param cause the root cause from the transaction API in use
     */
    public TransactionSystemException(String msg, Throwable cause) {
        super(msg, cause);
    }


    /**
     * Set an application exception that was thrown before this transaction exception,
     * preserving the original exception despite the overriding TransactionSystemException.
     *
     * @param ex the application exception
     * @throws IllegalStateException if this TransactionSystemException already holds an
     *                               application exception
     */
    public void initApplicationException(Throwable ex) {
        Assert.notNull(ex, "Application exception must not be null");
        if (this.applicationException != null) {
            throw new IllegalStateException("Already holding an application exception: " + this.applicationException);
        }
        this.applicationException = ex;
    }

    /**
     * Return the application exception that was thrown before this transaction exception,
     * if any.
     *
     * @return the application exception, or {@code null} if none set
     */
    @Nullable
    public final Throwable getApplicationException() {
        return this.applicationException;
    }

    /**
     * Return the exception that was the first to be thrown within the failed transaction:
     * i.e. the application exception, if any, or the TransactionSystemException's own cause.
     *
     * @return the original exception, or {@code null} if there was none
     */
    @Nullable
    public Throwable getOriginalException() {
        return (this.applicationException != null ? this.applicationException : getCause());
    }

    @Override
    public boolean contains(@Nullable Class<?> exType) {
        return super.contains(exType) || (exType != null && exType.isInstance(this.applicationException));
    }

}
